81924123 has 4 divisors (see below), whose sum is σ = 109232168. Its totient is φ = 54616080.

The previous prime is 81924119. The next prime is 81924127. The reversal of 81924123 is 32142918.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81924119) and next prime (81924127).

It is not a de Polignac number, because 81924123 - 2² = 81924119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81924127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13654018 + ... + 13654023.

It is an arithmetic number, because the mean of its divisors is an integer number (27308042).

Almost surely, 2^81924123 is an apocalyptic number.

81924123 is a deficient number, since it is larger than the sum of its proper divisors (27308045).

81924123 is a wasteful number, since it uses less digits than its factorization.

81924123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27308044.

The product of its digits is 3456, while the sum is 30.

The square root of 81924123 is about 9051.1945620454. The cubic root of 81924123 is about 434.3141046943.

It can be divided in two parts, 819 and 24123, that added together give a palindrome (24942).

The spelling of 81924123 in words is "eighty-one million, nine hundred twenty-four thousand, one hundred twenty-three".